The areas of Ellipsometry and Chromatography are both well developed. Ellipsometry involves causing a beam of electromagnetic radiation which is in a known polarization state to interact with a sample in a way that changes the polarization state thereof, and then applying mathematical regression to data pertaining to said change. Ellipsometric Parameters such as well known PSI (ψ) and DELTA (Δ) are typically determined by said procedure. Imaging ellipsometers are also known, and enable investigating samples over an area region thereof rather than at simply one small point. For instance, PSI (ψ) and DELTA (Δ) values for a multiplicity of points over an area of said sample can be determined and shown in a two, (or more), dimensions.
Chromatography is a technique for separation of analytes in mixtures of analytes present in a mobile phase, by interaction with a stationary phase. Various analyte constituents present in a mixture travel at different speeds, therefore enabling subtle differences in what is termed a “partition coefficient” with which each analyte presents to result in a different spatial distribution for each. Chromatography can be preparative, wherein the purpose is analyte separation for purification purposes, or it can be analytical which is focused on providing information on relative amounts of various analytes present and/or determining how various analytes move through a stationary phase over time. The latter application is more associated with the presently Claimed invention. In particular the present invention is properly thought of as primarily a version of planar chromatography in which the stationary phase is not merely, a flat paper or the like, but rather comprises a multiplicity of nano-structures that project non-normal to a surface thereof.
A Computer Search for Patents that combine Ellipsometer and Chromatography with an eye to providing images of various Jones or Mueller Matrix Elements for an area on a sample, returned one hit, a Patent to Frence, et al., U.S. Pat. No. 7,589,242. A similar search for Jones Matrix and Imaging Ellipsometer returned two Hits, a Patent to Woollam et al. U.S. Pat. No. 7,385,697 and a Patent to Acher, U.S. Pat. No. 8,908,180. Importantly, a Computer Search for Mueller Matrix and Chromatography returned no hits.
A known paper is titled “Imaging Ellipsometry of Graphene”, by Wurstbauer et al., Appl. Physics Lett., 97, 231901, 2010.
The present invention will be understood by reference to the following Specification.